Field of the Invention
The present invention relates to a workpiece loading and unloading method and device for loading a sheet workpiece into and for unloading a finished product from a plate processing machine such as, for example, a punch press and the like, and, in particular, to a workpiece loading and unloading method and device wherein the workpiece is loaded into and the finished product is unloaded from one side of the plate processing machine.
2. Description of the Prior Art
Conventionally, a sheet workpiece is loaded into a plate processing machine such as, for example, a plate punch press and the like, by a workpiece loading device positioned on one side of the plate processing machine, and the finished product after being processed in the plate processing machine is unloaded from the plate processing machine by a finished product unloading device generally positioned on the other side of the plate processing machine.
In this configuration, the positional relationship of the workpiece loading device, the plate processing machine, and the finished product unloading device is linear, therefore a comparatively large installation area is required, which can present a problem. A configuration wherein the workpiece loading device and the finished product unloading device are both positioned on one side of the plate processing machine is disclosed in, for example, Japanese Patent Publication No. S61-54492 (hereinafter referred to simply as the prior art). The configuration in this prior art wherein the workpiece loading device and the finished product unloading device are both positioned on the same side of provides the benefit of a comparably small installation area.
However, the workpiece loading device of the prior art has a configuration whereby, after the workpiece is secured and lifted by a suction device from a material pallet positioned adjacent to the finished product unloading device, the workpiece is conveyed to a position above the finished product unloading device, and from this position the workpiece is loaded into the plate processing machine.
Accordingly, in the prior art, the configuration of the workpiece loading device is complicated, which is also a problem.
In addition, in the prior art it is very difficult to classify and store workpiece and finished products of various shapes and sizes, so that unmanned, multiproduct, small number production runs are very difficult. This is another problem.
Further, in the prior art a support device which supports and loads the workpiece into the processing machine and a clamping device which clamps and unloads the finished product from the processing machine are provided separately. This complicates the configuration and is therefore another problem.
Yet further, because the workpiece is simply loaded into the plate processing machine in the conventional technology, it is necessary to provide another device for positioning the workpiece at a home-position in the plate processing machine. This is still another problem.
Also, in the conventional technology, when the end of the workpiece is clamped by the clamping devices provided on the workpiece loading device and the finished product unloading device, it is easy to create a bend in the end of the workpiece. This is undesirable and presents still another problem.